air condition INFINITI QX56 2008 Factory Service Manual

HAC-62
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
1. Start and run engine to operating temperature.
2. Turn the rear blower motor to maximum speed from the rear air control (front).
3. Turn rear air control (front) temperature control dial clockwise and then counterclockwise (REAR CTRL
indicator off).
4. Check for hot air at rear discharge air outlets in the maximum heat position and cold air at discharge air outlets in the maximum cold position.
Does the rear air control (front) operate properly?
YES >> GO TO 3.
NO >> Check rear air control (front). Refer to HAC-62, "
Air Mix Door Motor (Rear) Diagnosis Procedure".
3.CONFIRM SYMPTOM BY PERFORMING REAR AIR CO NTROL (REAR) AIR MIX DOOR MOTOR OPER-
ATIONAL CHECK
1. Press the REAR CTRL switch on rear air control (front) to send control to the rear air control (rear).
2. Turn rear air control (rear) temperature control dial slowly clockwise and then counterclockwise (REAR
CTRL indicator on).
3. Check for hot air at rear discharge air outlets in the maximum heat position and cold air at rear discharge
air outlets in the maximum cold position.
Does the rear air control (rear) operate properly?
YES >> GO TO 4.
NO >> Check rear air control (rear). Refer to HAC-58, "
Rear Air Control (Rear) Diagnosis Procedure #2".
4.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (FRONT) MODE OPERATIONAL CHECK
1. Press the REAR CTRL switch on rear air control (front) (REAR CTRL indicator off).
2. Press each mode switch and check for proper air discharge at the appropriate locations.
Does the rear air control (front) operate properly?
YES >> GO TO 5.
NO >> Check mode door motor (rear). Refer to HAC-66, "
Mode Door Motor (Rear) Diagnosis Proce-
dure".
5.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (REAR) MODE OPERATIONAL CHECK
1. Press the REAR CTRL switch on rear air control (f ront) to send control to the rear air control (rear).
2. Press each mode switch and check for proper air discharge at the appropriate locations.
Does the rear air control (rear) operate properly?
YES >> System OK.
NO >> Replace rear air control (rear). Refer to VTL-7, "
Removal and Installation".
Air Mix Door Motor (Rear) Diagnosis ProcedureINFOID:0000000001679806
DIAGNOSTIC PROCEDURE FOR INOPERATIVE AIR MIX DOOR MOTOR (REAR)
SYMPTOM:
• Temperature control (rear) operation is malfunctioning.
1.CHECK REAR AIR CONTROL (FRONT) POWER SUPPLY
1. Disconnect rear air control (front) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear air control (front) harness connec- tor R108 terminal 1 and ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK REAR AIR CONTROL (FRONT) LIN BUS VOLTAGE
Battery voltage should exist.
AWIIA0182ZZ
Revision: March 2010
2008 QX56

REAR AIR CONTROL SYSTEMHAC-63
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between rear air control (front) harness connector
R108 terminal 5 and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK REAR AIR CONTROL (FRONT) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between rear air control (front) harness con- nector R108 terminal 6 and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
4.CHECK LIN BUS VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor (rear) harness connector.
2. Check continuity between rear air control (front) harness con- nector R108 (B) terminal 5 and A/C auto amp. harness connec-
tor M50 (A) terminal 48.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
5.CHECK A/C AUTO AMP. FOR POWER AND GROUND FOR AIR MIX DOOR MOTOR (REAR)
1. Reconnect all disconnected parts.
2. Turn ignition switch ON.
3. Rotate temperature control dial (rear) to maximum heat.
4. Check voltage between A/C auto amp. harness connector M50 terminal 49 and terminal 50 while rotating temperature control
dial (front) to maximum cold.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN Battery voltage should exist.
AWIIA0183ZZ
Continuity should exist.
AWIIA0184ZZ
48 - 5
: Continuity should exist.
AWIIA0185ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 49 50 Rotate temp
control dial Battery
voltage
AWIIA0135ZZ
Revision: March 2010 2008 QX56

HAC-64
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector
M50 terminal 49 and terminal 50.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 7.
7.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (rear) harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 49, 50 and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace harness as necessary.
8.CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between A/C auto amp. harness connector M50 (A) terminal 49, 50 and the air mix door motor (rear) har-
ness connector B155 (B) terminal 1, 6.
Is the inspection result normal?
YES >> Replace air mix door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
9.CHECK A/C AUTO AMP. OWER AND GR OUND FOR AIR MIX DOOR MOTOR (REAR)
1. Rotate temperature control dial (front) to maximum cold.
2. Check voltage between A/C auto amp. harness connector M50 terminal 49 and terminal 50 while rotating temperature control
dial (rear) to maximum heat.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
10.CHECK A/C AUTO AMP. FOR AIR MIX DOOR MOTOR (REAR) PBR POWER AND GROUND
Continuity should exist.
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49 - Ground
: Continuity should not exist.
50 - Ground : Continuity should not exist.
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49 - 1 : Continuity should exist.
50 - 6 : Continuity should exist.
AWIIA0139ZZ
ConnectorTe r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 50 49 Rotate temp
control dial Battery
voltage
AWIIA0137ZZ
Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-65
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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1. Check voltage between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 11.
11 .CHECK PBR REFERENCE VO LTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12.
12.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the air mix door motor (rear) harness connector.
2. Check continuity between air mix door motor (rear) harness con- nector B155 (B) terminal 3, 2 and A/C auto amp. harness con-
nector M50 (A) terminal 28 and M49 (C) terminal 3.
Is the inspection result normal?
YES >> Replace air mix door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
13.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
Check continuity between A/C auto amp. harness connector M50
terminal 28 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
14.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M49, M50 28 35V
AWIIA0118ZZ
Continuity should exist.
AWIIA0120ZZ
28 - 3 : Continuity should exist.
3 - 2 : Continuity should exist.
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Continuity should not exist.
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Revision: March 2010 2008 QX56

HAC-66
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
Check voltage between A/C auto amp. harness connector M50 ter-
minal 33 and ground while rotating temperature control dial (rear)
from maximum cold to maximum heat.
Is the inspection result normal?
YES >> System OK.
NO >> GO TO 15.
15.CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the air mix door motor (rear) harness connector and A/C auto amp. harness connector.
3. Check continuity between air mix door motor (rear) harness con- nector B155 (B) terminal 4 and A/C auto amp. harness connec-
tor M50 (A) terminal 33.
Is the inspection result normal?
YES >> GO TO 16.
NO >> Repair or replace harness as necessary.
16.CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
Check continuity between A/C auto amp. harness connector M50
terminal 33 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
Mode Door Motor (Rear) Diagnosis ProcedureINFOID:0000000001679807
DIAGNOSTIC PROCEDURE INOPERATIVE MODE DOOR MOTOR (REAR)
1.CHECK REAR AIR CONTRO L (FRONT) POWER SUPPLY
1. Disconnect rear air control (front) harness connector.
2. Turn ignition switch ON.
3. Check voltage between rear air control (front) harness connec- tor R108 terminal 1 and ground.
Is the inspection results normal?
YES >> GO TO 2.
NO >> Repair harness or connector.
2.CHECK REAR AIR CONTROL (FRONT) LIN BUS VOLTAGE
Voltage
: Approx. 1V - 4.5V
AWIIA0140ZZ
Continuity should exist.
AWIIA0142ZZ
Continuity should not exist.
AWIIA0141ZZ
Battery voltage should exist.
AWIIA0182ZZ
Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-67
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between rear air control (front) harness connector
R108 terminal 5 and ground.
Is the inspection results normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.CHECK REAR AIR CONTROL (FRONT) GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Check continuity between rear air control (front) harness con- nector R108 terminal 6 and ground.
Is the inspection results normal?
YES >> GO TO 5.
NO >> Repair harness or connector.
4.CHECK LIN BUS VOLTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor (rear) harness connector.
2. Check continuity between rear air control (front) harness con- nector R108 (B) terminal 5 and A/C auto amp. harness connec-
tor M50 (A) terminal 48.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary.
5.CHECK A/C AUTO AMP. POWER AND GROUND FOR MODE DOOR MOTOR (REAR)
1. Reconnect all disconnected parts.
2. Turn ignition switch ON.
3. Press the mode switch to the FLOOR ( ) mode.
4. Check voltage between A/C auto amp. harness connector M50 terminal 43 and terminal 44 while pressing the mode switch to
the vent ( ) mode.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK MODE DOOR MOTOR AND CIRCUITS FOR OPEN Battery voltage should exist.
AWIIA0183ZZ
Continuity should exist.
AWIIA0184ZZ
48 - 5
: Continuity should exist.
AWIIA0185ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 43 44 Press
mode
switch
(rear) Battery
voltage
AWIIA0189ZZ
Revision: March 2010 2008 QX56

HAC-68
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector
M50 terminal 43 and terminal 44.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> GO TO 7.
7.CHECK MODE DOOR MOTOR CIRCUITS FOR SHORT TO GROUND
1. Disconnect the A/C auto amp. harness connector and mode door motor (rear) harness connector
2. Check continuity between A/C auto amp. harness connector
M50 terminal 43, 44 and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace harness as necessary.
8.CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN
Check continuity between A/C auto amp. harness connector M50 (A)
terminal 43, 44 and the mode door motor (rear) harness connector
B156 (B) terminal 5, 6.
Is the inspection result normal?
YES >> Replace mode door motor. Refer to VTL-26, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
9.CHECK A/C AUTO AMP. POWER AND GROUND FOR MODE DOOR MOTOR (REAR)
Check voltage between A/C auto amp. harness connector M50 ter-
minal 43 and terminal 44 while pressing the mode switch to the
FLOOR ( ) mode.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
10.CHECK A/C AUTO AMP. FOR MODE DOOR MOTOR (REAR) PBR POWER AND GROUND
Continuity should exist.
AWIIA0190ZZ
43 - Ground
: Continuity should not exist.
44 - Ground : Continuity should not exist.
AWIIA0192ZZ
5 - 43 : Continuity should exist.
6 - 44 : Continuity should exist.
AWIIA0191ZZ
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M50 44 43 Press
mode
switch (rear) Battery
voltage
AWIIA0196ZZ
Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-69
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Check voltage between A/C auto am p. harness connector M50 (A)
terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 14.
NO >> GO TO 11.
11 .CHECK PBR REFERENCE VO LTAGE AND GROUND CIRCUITS
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 (A) terminal 28 and M49 (B) terminal 3.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12
12.CHECK PBR REFERENCE VO LTAGE CIRCUIT FOR OPEN
1. Disconnect the mode door motor (rear) harness connector.
2. Check continuity between mode door motor (rear) harness con- nector B156 (B) terminal 3, 1 and A/C auto amp. harness con-
nector M49 (C) terminal 3, M50 (A) terminal 28.
Is the inspection result normal?
YES >> Replace mode door motor (rear). Refer to VTL-26,
"Removal and Installation".
NO >> Repair or replace harness as necessary.
13.CHECK PBR REFERENCE VOLTAGE CIRCUIT FOR SHORT TO GROUND
1. Turn ignition switch OFF.
2. Disconnect the A/C auto amp. harness connector.
3. Check continuity between A/C auto amp. harness connector M50 terminal 28 and ground.
Is the inspection result normal?
YES >> Replace the A/C auto amp. Refer to VTL-7, "Removal
and Installation".
NO >> Repair or replace harness as necessary.
14.CHECK PBR FEEDBACK VOLTAGE
Connector Te r m i n a l s
Voltage (Ap-
prox.)
(+) (-)
A/C auto amp.: M49, M50 28 35V
AWIIA0099ZZ
Continuity should exist.
AWIIA0101ZZ
28 - 1 : Continuity should exist.
3 - 3 : Continuity should exist.
AWIIA0102ZZ
Continuity should not exist.
AWIIA0100ZZ
Revision: March 2010 2008 QX56

HAC-70
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
REAR AIR CONTROL SYSTEM
Check voltage between A/C auto amp. harness connector M50 ter-
minal 30 and ground while cycling mode switch through all modes.
Is the inspection result normal?
YES >> System OK.
NO >> GO TO 15.
15.CHECK PBR FEEDBACK CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect the mode door motor harness connector and A/C auto amp. harness connector.
3. Check continuity between mode door motor harness connector B156 (B) terminal 2 and A/C auto amp. harness connector M50
(A) terminal 30.
Is the inspection result normal?
YES >> GO TO 16.
NO >> Repair or replace harness as necessary.
16.CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR SHORT TO GROUND
Check continuity between A/C auto amp. harness connector M50
terminal 30 and ground.
Is the inspection result normal?
YES >> Replace A/C auto amp. Refer to VTL-7, "Removal and
Installation".
NO >> Repair or replace harness as necessary. Voltage
: Approx. 1V - 4.5V
AWIIA0194ZZ
Continuity should exist.
AWIIA0195ZZ
Continuity should not exist.
AWIIA0193ZZ
Revision: March 2010 2008 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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MAGNET CLUTCH
System DescriptionINFOID:0000000001679808
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or OFF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset value, the compressor turns ON. The compressor turns
OFF when intake air temperature is lower than the pres et value. That preset value is dependent on the ambi-
ent temperature, refer to the following table.
Magnet Clutch Componen t Function CheckINFOID:0000000001679809
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Press the A/C switch.
3. Press vent switch ( ).
4. Display shows , A/C. Confirm that the compress or clutch engages (sound or visual inspection). (Dis-
charge air and blower speed will depend on ambient, in-vehicle and set temperatures.)
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK AMBIENT SENSOR
Check and verify ambient s ensor circuit. Refer to HAC-78, "
Ambient Sensor Diagnosis Procedure".
Ambient temperature ° C (°F) Compressor ON intake temperature °C ( °F) Compressor OFF intake temperature °C ( °F)
0 (32) 5.5 (42) 5.0 (41)
10 (50) 5.5 (42) 5.0 (41)
20 (68) 5.5 (42) 5.0 (41)
30 (86) 4.0 (39) 3.5 (38)
40 (104) 3.5 (38) 3.0 (37)
50 (122) 3.5 (38) 3.0 (37)
Revision: March 2010 2008 QX56